Conventional devices for rearing deep-sea organisms of this kind are disclosed in Patent Literatures 1 and 2, where they are referred to as an “in-water tank local temperature zone forming apparatus” and an “aquatic organism rearing apparatus” respectively.
The in-water tank local temperature zone forming apparatus disclosed in Patent Literature 1, or an rearing apparatus for aquatic organisms, in particular deep-sea organisms, includes a water tank made of a pressure tight container, a water stream generator to generate a water stream in one direction (lateral direction) in the water tank, a temperature zone generator to define a local temperature zone by heating or cooling a part of the water stream flowing on the bottom of the water tank, such as heater, and a temperature zone retainer to retain the local temperature zone defined by the temperature zone generator by preventing the temperature zone from being diffused over the whole water tank, such as nozzle. It is intended that deep-sea organisms such as shells that are less likely to be swept away by the water stream are reared in the temperature retainer.
The aquatic organism rearing apparatus disclosed in Patent Literature 2 includes a main water tank to house an aquatic organism together with water, a hot water supplying means to jet hot water upward from an jetting nozzle disposed on the bottom of the main water tank, and a hot water discharging means disposed at the upper part of the main water tank to discharge the rising hot water to the outside. The apparatus is configured to form a cold water zone and a local hot water zone in the water.